1. Field of the Invention
The present invention relates to an image forming device used in, for example, an exposure device which exposes an image-drawing region on a recording medium such as a printed circuit board or the like by a light beam or the like modulated in accordance with image information, so as to form an image in the image-drawing region.
2. Description of the Related Art
Conventionally, laser exposure devices, which are used as image forming devices for forming wiring patterns on printed circuit boards or the like for example, have been structured such that a printed circuit board, which is the object of image exposure, is set (or “loaded”, as will be used upon occasion) on a stage member for conveying, and while the stage member is moved at a predetermined speed in a subscanning direction, at a predetermined reading position, registration holes (alignment marks) provided at the four corners of the printed circuit board set on the stage member are picked-up by a CCD camera. Alignment processing for the image information is carried out by, in accordance with the position of the printed circuit board obtained by this image pickup, converting the coordinates of the region which is the object of image-drawing within the image-drawing coordinate system.
Then, at the predetermined exposure position, a laser beam, which is modulated on the basis of the image information and is deflected in the main scanning direction by a polygon mirror, scans and exposes a photosensitive coating film formed on the printed circuit board. In this way, exposure processing based on the image information is carried out, i.e., an image (latent image) corresponding to a wiring pattern is formed on a predetermined region (image-drawing region) of the printed circuit board. Note that the printed circuit board, on which the image (latent image) has been formed, is removed from the stage member (hereinafter called “unloading” upon occasion). The stage member, from which the printed circuit board has been removed, is moved to return to its initial position (is moved horizontally), and proceeds to the process for exposing the next printed circuit board (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2000-338432).
However, in this type of laser exposure device, exposure processing of printed circuit boards cannot be carried out during the time when the process of removing (unloading) the exposed printed circuit board from the stage member, the process of placing (loading) an unexposed printed circuit board on the stage member, and the process of moving the stage member to the reading position, are successively being carried out. Namely, the printed circuit board exposure processing is carried out intermittently at intervals corresponding to the aforementioned processes. Therefore, the manufacturing efficiency is poor. Thus, there has heretofore been the need to improve the manufacturing efficiency.